Next Generation Air Cycle Technology in Development
Principle of Next Generation Air Cycle direct loop
Our new development is the air cycle direct loop architecture for railway application. Compared to the existing air cycle reverse loop architecture used for ICE 3 trains since 2004, the new direct loop architecture is operating at overpressure and forcing the process air directly to the passenger coaches, similar to civil aircraft application. The new architecture is a little bit more complex but allows - due the overpressure and higher process air density - smaller components sizing and has further a number of positive effects.
Based on a recent 2-year field data collection of the ICE-3 air cycle compared to the ICE-T vapor cycle, a total cost of ownership (TCO) analysis was made. The evaluation of field test acquisition and TCO analysis by our Cost Assessment Tool (CAT) confirms that the existing air cycle system, in addition to environmental friendliness, is also economically at least equivalent to vapor cycle systems. For the average primary annual energy demand for cooling, the air cycle systems showed savings of 16 % to 28 % compared to the R134a systems considered. The evaluation of our Next Generation Air Cycle Architecture for the time being by simulation shows further improvement on energy savings and on the overall costs on TCO level.
Comparison of Total Cost of Ownership by Cost Assessment Tool (CAT)
Chart legend:
- ICE 3 Opt: Air Cycle Concept ICE 3, 2nd Series, maintenance optimized
- ICE-T bp: Vapor Cycle Concept ICE-T, additional with refrigerant hot-gas by-pass control
- ACS NG: Air Cycle Next Generation, open direct loop by simulation
- NRC - Non Recurring Cost ; RC - Recurring Cost; OC - Operating Cost (cooling & heating)
- MC - Maintenance Cost; ENVIRONM - Environment Costs
Commissioning of the demonstrator with colleagues from Liebherr-Aerospace Toulouse
A demonstrator of the Next Generation Air Cycle for Proof of Concept (TRL3) was built with use of some existing aerospace key components and tested positively at railway conditions at Liebherr Korneuburg climatic chamber.
The next steps are to set up Demonstrators TRL4/5 and TRL6 in the interfaces and installation limits of a new high speed train set and to enter for evaluation tests on train in early next decade.
